Perforated cutter foil for dry shavers



May 14, 1968 c. l.. RlNcK ET A. 3,382,580

PERFORATED CUTTER` FOIL FOR DRY SHAVERS Filed Nov. 26, 1965 mmh Alll ,l

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INVENTQRS BY 41/ @XM/PQM* MRNEYJ- United States Patent O PERFORATEDCUTTER FGIL FOR DRY SHAVERS Cornelis Ludwig Rinck andv Adam Koroncai,Klagenfurt,

Carinthia, Austria, assignors to Firma Carinthia ElektrogerateGesellschaft m.h.H., Karnten, Austria Filed Nov. 26, 1965, Ser. No.509,966 Claims priority, application Austria, Dec. 7, 1964, A 10,363/64Claims. (Cl. Btl-346.51)

ABSTRACT 0F THE DISCLOSURE A perforated cutter foil for dry shavershaving a plurality of diamond-shaped hair entry openings with adjacentsides of each making angles with one another of 60 and 120 respectively,and all the openings constituting a network which has groups of openingswith the groups having the principal diagonals extending in threediiferent directions which make angles of 120 with each other.

The invention relates to the construction of a cutter foil for dryShavers with a lower knife arranged beneath the foil.

It is known that in such apparatus both the quality of the shave andalso the time taken up for a good shave depends not only on theso-called opening ratio (relationship of the total area taken up by thehair entry openings to the total area of the cutter foil) but also onthe size and shape of the hair entry openings. Already numerous shapesfor the boundaries af these entry openings have been proposed, namelyfrom simple geometrical shapes, such as circle, ellipse, oval,rectangular, diamond, polygon, especially hexagon up to complicatedboundaries, eg. closed shapes provided with waves, points etc.

It is also known, that openings in the form of longitudinal slits areparticularly well suited to erect and grasp longer beard hairs, whichlie in the direction of the length of such openings, so that they can becut off. Moreover it is also already known, to distribute suchlongitudinal slits over the entire area of the foil with differentdirections of their longitudinal extents, to take account of the factthat the natural growth of the beard hairs, even in relatively smallareas of the skin, often follows sharply different directions. In allcutter foils which have hitherto become known with differently orientedhair entry openings of elongated shape there is however either, byreason of the presence of broad bars, a very unfavorable opening ratio,or there is a relatively small strength, which is unequal in variousdirections or in various areas by reason of the unfavorable arrangementof the bars between the openings.

These disadvantages are, according to the invention, avoided in a cutterfoil with a plurality of diamondshaped hair entry openings, in that theadjacent sides of the diamond-shaped hair entry openings make angleswith one another of 60 and 120 respectively, and that the totality ofthe openings constitutes a network, which predominantly or exclusivelycontains groups of diamondshaped openings, in which the directions ofthe principal diagonals of the openings make angles of 60 between eachother. In this way it is possible to arrange the openings alongside oneanother except for narrow bars, that is to say to achieve a high openingratio, but at the same time to ensure that bars extend in directionsuniformly angularly inclined to one another at 120, so that the cutterfoil is not inadmissibly weakened in any direction.

A particularly favourable arrangement is produced if the groups ofdiamond-shaped openings form six-pointed symmetrical stars. Then betweeneach two adjacent starshaped groups there can lie an additionaldiamond-shaped opening, or between three adjacent star-shaped groupsthere can lie a hexagonal opening.

There have been doubts hitherto against the employment of diamond-shapedhair entry openings, which apparently have been based on the fact thatthought has only been of an arrangement with the principal diagonalslying parallel. Thorough research has however shown that, with thediamond arrangement according to the invention, with consideration ofthe known rules for the dimensioning of hair entry openings, thediamond-shaped openings can be made so large that on the one hand noabnormal irritation of the skin occurs, but on the other hand longbeared hairs, even with very irregular beard growth, can be excellentlygrasped, while at the same time both a very large opening ratio can bechosen and with it a very good shaving performance can be achieved,because the network produced by the bars between the hair entryopenings, in which at the junctions up to six bars meet, permits thebars to be chosen especially narrow, without the strength of the foilsuffering by it.

The invention will now be explained in more detail with reference to thedrawings which have been kept schematic. FIGURE 1 shows the group ofhair entry openings in the form of a six-pointed symmetrical star whichis preferably employed within the scope of the invention, while FIGURES2, 3 and 4 show various possibilities of arranging such star-shapedgroups in relation to one another. FIGURE 5 shows an arrangement ofhexagonal groups alongside one another according to another way ofcarrying out the invention.

The group of hair entry openings shown in FIGURE l consists of sixopenings 1 of diamond shape, in which the adjacent sides of thediamond-shaped openings make angles with one another of 60 and 120respectively. Six openings 1 of this kind are assembled into asymmetrical six-pointed star, While `between the openings there onlyremain narrow bars 2 and six of such bars which extend in threedirections displaced angularly from one another by l20 meet at junctions3. Some corners of the diamond-shaped hair entry openings, preferablythe acute corners 4, can be rounded.

In FIGURES 2 to 4 there are shown schematic portions of cutter foils, inwhich star-shaped groups according to FIGURE 1 are assembled in variousnetwork arrangements. The individual star groups are shaded to permitclearer identification.

In the arrangement according lto FIGURE 2 there lie between each twostar-shaped groups 5 additional diamond-shaped openings 6, while in thearrangement according to FIGURE 3 between each three adjacent starshapedgroups 5 there are openings 7 in the form of regular hexagons.

The arrangement according to FIGURE 4 is similar to that according toFIGURE 3, except that in this case the hexagonal openings are divided bythree bars angularly displaced from one another by into diamond-shapedopenings of the same size as the openings 1.

In the arrangement according -to FIGURE 5 the individual groups arehexagonal, and inside each hexagon boundary there lie twelvediamond-shaped openings 1, of which each four have the same direction ofthe principal diagonal, While the result is three directions ofprincipal diagonal, which are angularly displaced from one another by120.

It can be seen that, in each of the examples of construction shown, theprincipal diagonals of the diamondshaped hair entry openings extend inthree directions which are angularly displaced from one another by 120,and that the bars between these openings are also angularly displacedfrom one another by 120. Thus in all 3 directions a good grasping of thebeard hairs is ensured, and furthermore an adequate strength in alldirections is maintained. Over and above the arrangements of openingsshown, the diamonds with angles of 60 and 120 respectively also permitnumerous other groupings, and assemblies of groups into networks.

We claim:

1. Perforated cutter foil for dry Shavers, comprising a plurality ofdiamond-shaped hair entry openings, the adiacent sides of each of saiddiamond-shaped hair entry openings making angles with one another of 60degrees and 120 degrees respectively, and the .totality of the openingsconstituting a network which contains groups of at least threediamond-shaped openings abutting at a common apex, in which groups theprincipal and longer diagonals of the openings extend in three differentdirections which make angles of 60 degrees with each other.

2. Perforated cutter foil according to claim 1 in which the networkcontains groups of six diamond-shaped openings abutting at a common apexto form a six-pointed symmetrical star.

3. Perforated cutter foil according to claim 1 in which the networkcontains groups of three diamond-shaped openings abutting at a commonapex to form an equilateral hexagon.

4. Perforated cutter foil according to claim 1 in which the networkcontains groups of six diamond-shaped openings abutting at a common apexto form a six-pointed symmetrical star, each of said groups of openingshaving two apices in common with a similar adjacent group of openings,while between two adjacent groups there is an additional diamond-shapedopening.

5. Perforated cutter foil according to claim 1 in which the networkcontains two types of groups of openings, of which one group is sixdiamond-shaped openings which abut at a common apex to form asix-pointed symmetrical star and a group of three diamond-shapedopenings abut at a common apex to form an equilateral hexagon, eachgroup of openings having one apex in common with a similar adjacentgroup of openings.

References Cited UNITED STATES PATENTS 2,183,442 12/1939 Blackwell30--346.51 X 2,198,833 4/ 1940 Muros 30--346.51 X 2,223,156 11/1940Benner 30a-346.51 X 2,289,323 7/1942 Dettle 'S0-346.51 X 2,292,8588/1942 Alexay Sti-346.51 X 2,360,785 10/1944 Mehl 30-346.51 X 2,573,75811/1951 Bailey .3G-346.51 X 2,824,367 2/1958 McWilliams 30-4-1.53,093,899 6/ 1963 Futterer E50-346.51 X

FOREIGN PATENTS 663,487 8/ i938 Germany. 64,863 5/ 1942 Norway.

) MYRON C. KRUSE, Primary Examiner.

